[linux.git] / lib / kstrtox.c

/*
 * Convert integer string representation to an integer.
 * If an integer doesn't fit into specified type, -E is returned.
 *
 * Integer starts with optional sign.
 * kstrtou*() functions do not accept sign "-".
 *
 * Radix 0 means autodetection: leading "0x" implies radix 16,
 * leading "0" implies radix 8, otherwise radix is 10.
 * Autodetection hints work after optional sign, but not before.
 *
 * If -E is returned, result is not touched.
 */
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/math64.h>
#include <linux/export.h>
#include <linux/types.h>
#include <asm/uaccess.h>
#include "kstrtox.h"

const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
{
	if (*base == 0) {
		if (s[0] == '0') {
			if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
				*base = 16;
			else
				*base = 8;
		} else
			*base = 10;
	}
	if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
		s += 2;
	return s;
}

/*
 * Convert non-negative integer string representation in explicitly given radix
 * to an integer.
 * Return number of characters consumed maybe or-ed with overflow bit.
 * If overflow occurs, result integer (incorrect) is still returned.
 *
 * Don't you dare use this function.
 */
unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p)
{
	unsigned long long res;
	unsigned int rv;
	int overflow;

	res = 0;
	rv = 0;
	overflow = 0;
	while (*s) {
		unsigned int val;

		if ('0' <= *s && *s <= '9')
			val = *s - '0';
		else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f')
			val = _tolower(*s) - 'a' + 10;
		else
			break;

		if (val >= base)
			break;
		/*
		 * Check for overflow only if we are within range of
		 * it in the max base we support (16)
		 */
		if (unlikely(res & (~0ull << 60))) {
			if (res > div_u64(ULLONG_MAX - val, base))
				overflow = 1;
		}
		res = res * base + val;
		rv++;
		s++;
	}
	*p = res;
	if (overflow)
		rv |= KSTRTOX_OVERFLOW;
	return rv;
}

static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
{
	unsigned long long _res;
	unsigned int rv;

	s = _parse_integer_fixup_radix(s, &base);
	rv = _parse_integer(s, base, &_res);
	if (rv & KSTRTOX_OVERFLOW)
		return -ERANGE;
	rv &= ~KSTRTOX_OVERFLOW;
	if (rv == 0)
		return -EINVAL;
	s += rv;
	if (*s == '\n')
		s++;
	if (*s)
		return -EINVAL;
	*res = _res;
	return 0;
}

int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
{
	if (s[0] == '+')
		s++;
	return _kstrtoull(s, base, res);
}
EXPORT_SYMBOL(kstrtoull);

int kstrtoll(const char *s, unsigned int base, long long *res)
{
	unsigned long long tmp;
	int rv;

	if (s[0] == '-') {
		rv = _kstrtoull(s + 1, base, &tmp);
		if (rv < 0)
			return rv;
		if ((long long)(-tmp) >= 0)
			return -ERANGE;
		*res = -tmp;
	} else {
		rv = kstrtoull(s, base, &tmp);
		if (rv < 0)
			return rv;
		if ((long long)tmp < 0)
			return -ERANGE;
		*res = tmp;
	}
	return 0;
}
EXPORT_SYMBOL(kstrtoll);

/* Internal, do not use. */
int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
{
	unsigned long long tmp;
	int rv;

	rv = kstrtoull(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (unsigned long long)(unsigned long)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(_kstrtoul);

/* Internal, do not use. */
int _kstrtol(const char *s, unsigned int base, long *res)
{
	long long tmp;
	int rv;

	rv = kstrtoll(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (long long)(long)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(_kstrtol);

int kstrtouint(const char *s, unsigned int base, unsigned int *res)
{
	unsigned long long tmp;
	int rv;

	rv = kstrtoull(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (unsigned long long)(unsigned int)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtouint);

int kstrtoint(const char *s, unsigned int base, int *res)
{
	long long tmp;
	int rv;

	rv = kstrtoll(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (long long)(int)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtoint);

int kstrtou16(const char *s, unsigned int base, u16 *res)
{
	unsigned long long tmp;
	int rv;

	rv = kstrtoull(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (unsigned long long)(u16)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtou16);

int kstrtos16(const char *s, unsigned int base, s16 *res)
{
	long long tmp;
	int rv;

	rv = kstrtoll(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (long long)(s16)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtos16);

int kstrtou8(const char *s, unsigned int base, u8 *res)
{
	unsigned long long tmp;
	int rv;

	rv = kstrtoull(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (unsigned long long)(u8)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtou8);

int kstrtos8(const char *s, unsigned int base, s8 *res)
{
	long long tmp;
	int rv;

	rv = kstrtoll(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (long long)(s8)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtos8);

#define kstrto_from_user(f, g, type)					\
int f(const char __user *s, size_t count, unsigned int base, type *res)	\
{									\
	/* sign, base 2 representation, newline, terminator */		\
	char buf[1 + sizeof(type) * 8 + 1 + 1];				\
									\
	count = min(count, sizeof(buf) - 1);				\
	if (copy_from_user(buf, s, count))				\
		return -EFAULT;						\
	buf[count] = '\0';						\
	return g(buf, base, res);					\
}									\
EXPORT_SYMBOL(f)

kstrto_from_user(kstrtoull_from_user,	kstrtoull,	unsigned long long);
kstrto_from_user(kstrtoll_from_user,	kstrtoll,	long long);
kstrto_from_user(kstrtoul_from_user,	kstrtoul,	unsigned long);
kstrto_from_user(kstrtol_from_user,	kstrtol,	long);
kstrto_from_user(kstrtouint_from_user,	kstrtouint,	unsigned int);
kstrto_from_user(kstrtoint_from_user,	kstrtoint,	int);
kstrto_from_user(kstrtou16_from_user,	kstrtou16,	u16);
kstrto_from_user(kstrtos16_from_user,	kstrtos16,	s16);
kstrto_from_user(kstrtou8_from_user,	kstrtou8,	u8);
kstrto_from_user(kstrtos8_from_user,	kstrtos8,	s8);
Commit	Line	Data
33ee3b2e AD	1	/*
	2	* Convert integer string representation to an integer.
	3	* If an integer doesn't fit into specified type, -E is returned.
	4	*
	5	* Integer starts with optional sign.
	6	* kstrtou*() functions do not accept sign "-".
	7	*
	8	* Radix 0 means autodetection: leading "0x" implies radix 16,
	9	* leading "0" implies radix 8, otherwise radix is 10.
	10	* Autodetection hints work after optional sign, but not before.
	11	*
	12	* If -E is returned, result is not touched.
	13	*/
	14	#include <linux/ctype.h>
	15	#include <linux/errno.h>
	16	#include <linux/kernel.h>
	17	#include <linux/math64.h>
8bc3bcc9	18	#include <linux/export.h>
33ee3b2e	19	#include <linux/types.h>
c196e32a	20	#include <asm/uaccess.h>
1dff46d6	21	#include "kstrtox.h"
33ee3b2e	22
1dff46d6	23	const char _parse_integer_fixup_radix(const char s, unsigned int *base)
33ee3b2e	24	{
1dff46d6	25	if (*base == 0) {
33ee3b2e AD	26	if (s[0] == '0') {
33ee3b2e AD	27	if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
1dff46d6	28	*base = 16;
33ee3b2e	29	else
1dff46d6	30	*base = 8;
33ee3b2e	31	} else
1dff46d6	32	*base = 10;
33ee3b2e	33	}
1dff46d6	34	if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
33ee3b2e	35	s += 2;
1dff46d6 AD	36	return s;
	37	}
	38
	39	/*
	40	* Convert non-negative integer string representation in explicitly given radix
	41	* to an integer.
	42	* Return number of characters consumed maybe or-ed with overflow bit.
	43	* If overflow occurs, result integer (incorrect) is still returned.
	44	*
	45	* Don't you dare use this function.
	46	*/
690d137f	47	unsigned int _parse_integer(const char s, unsigned int base, unsigned long long p)
1dff46d6	48	{
690d137f	49	unsigned long long res;
1dff46d6 AD	50	unsigned int rv;
1dff46d6 AD	51	int overflow;
33ee3b2e	52
690d137f	53	res = 0;
1dff46d6 AD	54	rv = 0;
1dff46d6 AD	55	overflow = 0;
33ee3b2e AD	56	while (*s) {
	57	unsigned int val;
	58
	59	if ('0' <= s && s <= '9')
	60	val = *s - '0';
	61	else if ('a' <= _tolower(s) && _tolower(s) <= 'f')
	62	val = _tolower(*s) - 'a' + 10;
78be959e	63	else
1dff46d6	64	break;
33ee3b2e AD	65
33ee3b2e AD	66	if (val >= base)
1dff46d6	67	break;
690d137f DH	68	/*
	69	* Check for overflow only if we are within range of
	70	* it in the max base we support (16)
	71	*/
	72	if (unlikely(res & (~0ull << 60))) {
	73	if (res > div_u64(ULLONG_MAX - val, base))
	74	overflow = 1;
	75	}
	76	res = res * base + val;
1dff46d6	77	rv++;
33ee3b2e AD	78	s++;
33ee3b2e AD	79	}
690d137f	80	*p = res;
1dff46d6 AD	81	if (overflow)
	82	rv \|= KSTRTOX_OVERFLOW;
	83	return rv;
	84	}
	85
	86	static int _kstrtoull(const char s, unsigned int base, unsigned long long res)
	87	{
	88	unsigned long long _res;
	89	unsigned int rv;
	90
	91	s = _parse_integer_fixup_radix(s, &base);
	92	rv = _parse_integer(s, base, &_res);
	93	if (rv & KSTRTOX_OVERFLOW)
	94	return -ERANGE;
	95	rv &= ~KSTRTOX_OVERFLOW;
	96	if (rv == 0)
	97	return -EINVAL;
	98	s += rv;
	99	if (*s == '\n')
	100	s++;
	101	if (*s)
33ee3b2e	102	return -EINVAL;
1dff46d6	103	*res = _res;
33ee3b2e AD	104	return 0;
	105	}
	106
	107	int kstrtoull(const char s, unsigned int base, unsigned long long res)
	108	{
	109	if (s[0] == '+')
	110	s++;
	111	return _kstrtoull(s, base, res);
	112	}
	113	EXPORT_SYMBOL(kstrtoull);
	114
	115	int kstrtoll(const char s, unsigned int base, long long res)
	116	{
	117	unsigned long long tmp;
	118	int rv;
	119
	120	if (s[0] == '-') {
	121	rv = _kstrtoull(s + 1, base, &tmp);
	122	if (rv < 0)
	123	return rv;
	124	if ((long long)(-tmp) >= 0)
	125	return -ERANGE;
	126	*res = -tmp;
	127	} else {
	128	rv = kstrtoull(s, base, &tmp);
	129	if (rv < 0)
	130	return rv;
	131	if ((long long)tmp < 0)
	132	return -ERANGE;
	133	*res = tmp;
	134	}
	135	return 0;
	136	}
	137	EXPORT_SYMBOL(kstrtoll);
	138
	139	/* Internal, do not use. */
	140	int _kstrtoul(const char s, unsigned int base, unsigned long res)
	141	{
	142	unsigned long long tmp;
	143	int rv;
	144
	145	rv = kstrtoull(s, base, &tmp);
	146	if (rv < 0)
	147	return rv;
	148	if (tmp != (unsigned long long)(unsigned long)tmp)
	149	return -ERANGE;
	150	*res = tmp;
	151	return 0;
	152	}
	153	EXPORT_SYMBOL(_kstrtoul);
	154
	155	/* Internal, do not use. */
	156	int _kstrtol(const char s, unsigned int base, long res)
	157	{
	158	long long tmp;
	159	int rv;
	160
	161	rv = kstrtoll(s, base, &tmp);
	162	if (rv < 0)
	163	return rv;
	164	if (tmp != (long long)(long)tmp)
	165	return -ERANGE;
	166	*res = tmp;
	167	return 0;
168	}
169	EXPORT_SYMBOL(_kstrtol);
170
171	int kstrtouint(const char s, unsigned int base, unsigned int res)
172	{
173	unsigned long long tmp;
174	int rv;
175
176	rv = kstrtoull(s, base, &tmp);
177	if (rv < 0)
178	return rv;
179	if (tmp != (unsigned long long)(unsigned int)tmp)
180	return -ERANGE;
181	*res = tmp;
182	return 0;
183	}
184	EXPORT_SYMBOL(kstrtouint);
185
186	int kstrtoint(const char s, unsigned int base, int res)
187	{
188	long long tmp;
189	int rv;
190
191	rv = kstrtoll(s, base, &tmp);
192	if (rv < 0)
193	return rv;
194	if (tmp != (long long)(int)tmp)
195	return -ERANGE;
196	*res = tmp;
197	return 0;
198	}
199	EXPORT_SYMBOL(kstrtoint);
200
201	int kstrtou16(const char s, unsigned int base, u16 res)
202	{
203	unsigned long long tmp;
204	int rv;
205
206	rv = kstrtoull(s, base, &tmp);
207	if (rv < 0)
208	return rv;
209	if (tmp != (unsigned long long)(u16)tmp)
210	return -ERANGE;
211	*res = tmp;
212	return 0;
213	}
214	EXPORT_SYMBOL(kstrtou16);
215
216	int kstrtos16(const char s, unsigned int base, s16 res)
217	{
218	long long tmp;
219	int rv;
220
221	rv = kstrtoll(s, base, &tmp);
222	if (rv < 0)
223	return rv;
224	if (tmp != (long long)(s16)tmp)
225	return -ERANGE;
226	*res = tmp;
227	return 0;
228	}
229	EXPORT_SYMBOL(kstrtos16);
230
231	int kstrtou8(const char s, unsigned int base, u8 res)
232	{
233	unsigned long long tmp;
234	int rv;
235
236	rv = kstrtoull(s, base, &tmp);
237	if (rv < 0)
238	return rv;
239	if (tmp != (unsigned long long)(u8)tmp)
240	return -ERANGE;
241	*res = tmp;
242	return 0;
243	}
244	EXPORT_SYMBOL(kstrtou8);
245
246	int kstrtos8(const char s, unsigned int base, s8 res)
247	{
248	long long tmp;
249	int rv;
250
251	rv = kstrtoll(s, base, &tmp);
252	if (rv < 0)
253	return rv;
254	if (tmp != (long long)(s8)tmp)
255	return -ERANGE;
256	*res = tmp;
257	return 0;
258	}
259	EXPORT_SYMBOL(kstrtos8);
c196e32a AD	260
	261	#define kstrto_from_user(f, g, type) \
	262	int f(const char __user s, size_t count, unsigned int base, type res) \
	263	{ \
	264	/* sign, base 2 representation, newline, terminator */ \
	265	char buf[1 + sizeof(type) * 8 + 1 + 1]; \
	266	\
	267	count = min(count, sizeof(buf) - 1); \
	268	if (copy_from_user(buf, s, count)) \
	269	return -EFAULT; \
	270	buf[count] = '\0'; \
	271	return g(buf, base, res); \
	272	} \
	273	EXPORT_SYMBOL(f)
	274
	275	kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long);
	276	kstrto_from_user(kstrtoll_from_user, kstrtoll, long long);
	277	kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long);
	278	kstrto_from_user(kstrtol_from_user, kstrtol, long);
	279	kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int);
	280	kstrto_from_user(kstrtoint_from_user, kstrtoint, int);
	281	kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
	282	kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
	283	kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
	284	kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);